The role of growth factors for neovascularization of CNS tumor

1)人和大鼠脑鼓瘤组织中VEGH、VEGFR和VEGFmRNA的表达。血管内皮生长因子（Vascular endothelial growth factor， VEGF）是胚胎发育和肿瘤中血管的一种分泌性血管生成调节剂或生长因子。我们在人和大鼠脑中进行了VEGF、VEGFR - 1和VEGFmRNA的表达。为探讨VEGF在肿瘤空泡系统发育中的作用及微环境的影响，采用免疫组化和原位杂交技术分析了人脑肿瘤和大鼠移植肿瘤中VEGF、VEGFR（flt-1）的存在及VEGF mRNA的表达。我们用手术切除的星形细胞瘤和转移瘤，皮下和脑内移植的动物与ENU诱导的大鼠胶质瘤培养细胞（C6）。在星形细胞肿瘤和转移性肿瘤中，VEGF和VEGF的表达在形成肾小球增生的新形成的微血管中被识别。内皮细胞无表达，无肾小球增生。在移植肿瘤中，肿瘤细胞的增殖活性和新形成的微血管形态在不同肿瘤间均无显著差异。两种肿瘤新形成的微血管均未见肾小球增生。内皮细胞中可以识别VEGF和VEGFR的表达，但VEGF mRNA不表达。在脑肿瘤中，血管周围可见肿瘤浸润，皮下可见肿瘤浸润，皮下可见假乳样区，假乳样区肿瘤细胞中VEGF mRNA表达升高。移植肿瘤被认为受移植区域的影响。移植肿瘤的生物学和形态学特征被认为受移植区微环境的影响。2) VEGF、VEGFR和VEGFmRNA在大鼠血管形成中的表达。为探讨正常生理状态下VEGF在血管系统发育中的作用，采用免疫组化和原位杂交技术分析新生大鼠血管内皮生长因子的存在及VEGF mRNA的表达。24只新生大鼠分别于出生后1、3、5、7、10和14天手术切除大脑。出生后第1天至第7天毛细血管内皮细胞中均可检测到VEGF mRNA的表达，10天时表达量最大。10天时表达减少，14天时无表达。VEGFmRNA在所有标本的神经元中均上调，特别是在浦肯野细胞和海马神经元中。最大表达在出生后5天被识别，并逐渐减少。使用抗VEGF单克隆抗体进行免疫组化染色得到了类似的结果，这些结果高度提示在大鼠血管发生中建立了刺激新生血管生长的自分泌和旁分泌信号转导。3)紧密连接相关蛋白与肿瘤增殖活性的关系。为了阐明脑肿瘤新生血管保护血脑屏障（BBB）功能的机制，我们研究了MDR1基因产物、p -糖蛋白（PgP）和紧密连接相关蛋白的表达。Zo-1免疫组化。采用抗PgP和抗ZO-1单抗检测30例脑肿瘤，比较VEGF、VEGFR和PCNA的表达。PGP和Zo-1在原发性胶质瘤新形成的微血管内皮细胞中有阳性反应，而在脑膜瘤中无阳性反应。虽然所有转移癌新生微血管内皮细胞均呈阳性反应；原发癌中可见阴性反应。与胶质母细胞瘤和转移性癌周围脑组织边界新形成的微血管中形成肾小球增生的内皮细胞相比，抗PgP和Zo-1的反应较弱。血脑屏障相关蛋白阳性反应与VEGF表达及增殖活性呈负相关。这些结果表明，新形成的微血管内皮细胞保存了血脑屏障的基础。少

1) Expression of VEGH, VEGFR and VEGFmRNA in human and rat brain tymumor.Vascular endothelial growth factor (VEGF) is a secreted angiogeneic regulator or growth factor of blood vessels during embryonic development and in tumors. We performed expression of VEGF, VEGFR - 1 and VEGFmRNA in human and rat brain.To evaluate to the role of VEGF in the development of vacular system in tumor, and the effects of the microcircumstance, we analyzed existence VEGF, VEGFR(flt-1) and expression of VEGF mRNA using immunohistochemistry and in situ hybridization in human brain tumors and rat trasnsplanted tumors. We used surgically removed astrocytic tumors and metastatic tumors, subcutaneous and intracerebral transplanted animals with ENU induced rat glioma cultured cell (C6). In astrocytic tumors and metastatic tumors, expression of VEGF and VEGER were recognized in newly-formed micro blood vessels which form glomeruloid proliferations. But no expression in endothelial cells without glomeruloid prolif … More erations. In transplanted tumors, no significant differences of proliferative activities of tumor cells and the morphlogy of newly-formed micro blood vessels were identified in each tumors. No glomeruolid proliferations were noted in newly formed micro blood vessels in both tumors.Expression of VEGF and VEGFR were recognized in the endothelial cells but no expression of VEGF mRNA. In cerebral tumor, tumor infiltrations were noted in perivascular infilatrarions was recognized in subcutaneous tumor, pseduopalisading patterns were recognized in the subcutaneous ones and the expression of VEGF mRNA were increased in the tumor cells of pseudopalisading areas. The transplanted tumors were though to be affected by of transplanted areas. The biological and morpholgical characteristics the transplanted tumors were thought to be affected by the microcircumstance of transplanted areas.2) Expression in VEGF, VEGFR, and VEGFmRNA in rat vasculognesis.To evaluate to the role of VEGF in the development of vascular system in normal physiological state, we were analyzed the existence VEGF and expression of VEGF mRNA using immunohistochemistry and in situ hybridization in newborn rats. 24 newborn rat brains were surgically removed at 1, 3, 5, 7, 10 and 14 days after the birth. The expression of VEGF mRNA was recognized in the endothelial cells of capillaries from one day to the 7 days after the birth, the maximum expressions were demonstarated at 10 days. The expression is decreased at 10 days and no expressions are recognized at 14 days after birth. VEGFmRNA was up regulated in the neurons of all specmens, especially in Purukinje cells and neuron at hippocampi. Maximal expressions are recognized at 5days after birth and decreased grandually. Immunohistochemical stainngs using anti VEGF monoclonal antibody obtained similar findings these findings highly suggested that autocrine and paracrine signal transduction for the stimulation of the growth of neovasculature were established in rat vasculogenesis.3) The relationship of tight junction related protein and tumor proliferative actoivities.To elucidate the neovasculature of brain tumors preserve the blood brain barrier (BBB) functions, we studies the expressions of the MDR1 gene products, P-glycoprotein(PgP) and tight juinction related protein. Zo-1 using immunohistochemistry. 30 brain tumors were examined using an anti PgP and an anti ZO-1 Mab, and comparing the expression of VEGF, VEGFR and PCNA.. Positive reactions for PGP and Zo-1 were recoginzed in the endothelial cells in newly formed micro-blloc vessels in primariy glioma but not those in the meningiomas. Although endothelial cells in newly formed micro-blood vessels of all metastatic carcinomas showed positive reaction; negative reactions were seen in those of the primary carcinomas. Weak reactions for anti PgP and Zo-1 compared to those of endothelial cells forming glomeruloid proliferations in newly formed micro-blood vessles in glioblastomas and at the border of the surrounding cerebral tissue of metastatic carcinomas. The negative relations between positive reactions for BBB related proteins, and the expression of VEGF and the proliferative activities were recognized. These findings suggested that the endothelial cells in newly formed micro-blood vessels preserved the fundtions of BBB. Less